Exfoliation of surface oxide from continuously cast copper bar in conjunction with inline hot rolling

ABSTRACT

A method is provided for removal of surface oxide from a continuously cast copper bar preparatory to inline hot rolling, wherein solidified bar continuously advancing from a continuous caster is directed to a continuous hot rolling mill, comprising: passing said advancing bar, being at hot rolling temperature, through a spray zone of selected quench capacity and impulse, such that for each segment of said bar passing through said spray zone, said oxide is quenched to a black heat but is not ablated and said underlying bar is subjected to a shallow quench; said spray zone being situated in close proximity to but selectively spaced upcourse from the first rolls of said hot rolling mill such that there is insufficient time for substantial reheating of said quenched oxide during the approach to said first rolls; whereupon as quenched segments of the advancing bar progressively approach said first rolls and said underlying bar begins to deform just prior to roll contact, said oxide spalls off the bar surfaces substantially. Thus, the protective copper oxide is not removed from the bar surface until immediately prior to roll contact thereby preventing reoxidation of the bar surface; and further, since the spray is necessarily nonablative in magnitude there is minimal effect on the temperature and hot forming characteristics of the underlying bar.

BACKGROUND OF THE INVENTION

This invention relates generally to removal of surface oxide from an elongate copper workpiece preparatory to hot rolling and relates specifically to spray descaling of continuously cast copper bar prior to inline hot rolling.

The manufacture of copper rod in a continuous casting system is an integrated process in which a continuous bar of indefinite length is continuously solidified in a continuous casting machine and directed from the exit point of the casting machine to an inline continuous rolling mill wherein the nascent bar is hot formed into rod while still in a plastic state. The surface of the nascent bar immediately oxidizes as soon as the hot bar surface is exposed to the atmosphere upon emerging from the casting channel. This surface oxidation preferably should be removed before the bar enters the rolling mill, otherwise p6(E) and 6(F) are waveform diagrams of signals output by the orientation circuit 12 of FIG. 6(A).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An embodiment of the present invention will now be described in detail in conjunction with the drawings. FIG. 1 is a sectional view illustrating a magnetic body mounting structure of a magnetic sensor according to the present invention; FIG. 2 is a sectional view of a section taken along line 2--2 of FIG. 1 as; and FIG. 3 is a side view as seen from the B direction.

In the Figures, numeral 1 denotes a spindle serving as a rotary shaft, and numeral 2 represents an accommodating ring equipped with an accommodating portion for receiving a magnetic body 3. The accommodating ring 2 is formed to have an inner diameter nearly equal to the diameter of the spindle 1 and has a first cut-out portion 2a on its inner circumferential side and a second cut-out portion 2b on its outer circumferential side (FIG. 4). Numeral 4 designates an annular cover body fixedly secured to and integrated with the accommodating ring 2 on the circumferential surface of the spindle 1 by bolts 5. The annular cover body is formed to include a first projection 4a on the side thereof facing the circumferential surface of spindle 1, and a second projection 4b fitted into the second cut-out portion 2b on the outer circumferential side of the accommodating ring 2. Numerals 6, 7 denote a pair of wedge-shaped, annular fastening elements fitted onto the circumferential surface of the spindle 1 in such a manner that their tapered portions oppose each other.

As shown in FIG. 3, the accommodating ring 2 is fixedly secured to and integrated with the cover body 4 by the bolts 5 provided at four locations on the cover body 4. When this is carried out, the fastening elements 6, 7 are urged into the first cut-out portion 2a of accommodating ring 2, thereby enabling the magnetic body 3 inside the accommodating ring 2 to be fixedly secured at a prescribed position on the circumferential surface of the spindle 1, as clearly shown in FIG. 2. However, a force imbalance will act upon the magnetic body 3 as the spindle 1 rotates if the spindle is provided with the magnetic body 3 solely at the prescribed position. Accordingly, balance is achieved by providing an attracting magnet 8 at a position symmetrically located with respect to the magnetic body 3, taking the cener line 0 of the spindle as center. It should be noted that any object having a mass that will balance the magnetic body 3 will suffice, and this object need not necessarily be the magnet 8.

A rubber magnet or a magnet made of plastic and exhibiting flexibility perferably is used as the magnetic body 3.

The structure for mounting the magnetic body 3 in the magnetic sensor system of the present invention will now be described in detail with reference to FIGS. 4 and 5.

FIG. 4 is a sectional view of the accommodating ring 2 and cover body 4 in the process of being secured to each other, and FIG. 5 is a sectional view showing the accommodating ring 2 and cover body 4 in a state where they are nearly secured to each other. Both views are enlargements of the portion I shown in FIG. 1.

The first cut-out portion 2a of the accommodating ring 2 receives the wedge-shaped, annular fastening elements 6, 7 in such a manner that their tapered portions oppose each other. The accommodating ring 2 is formed to include the cut-out portion 2b into which the second projection 4b of cover body 4 is fitted, as well as female screw portions into which the bolts 5 are screwed. When the cover body 4 is attached to the accommodating ring 2 by the male-threaded bolts 5, the first projection 4a is thrust into the cut-out portion 2a to slide the leading fastening element 6, and the second projection 4b is fitted into the cut-out portion 2b, thereby fixedly securing the accommodating ring 2 to the spindle 1. By thus screwing the bolts 5 into the female screw portions of the accommodating ring 2, the accommodating ring 2 and cover body 4 are substantially secured to each other, as shown in FIG. 5.

When the first projection 4a slides the fastening element 6 axially of the spindle 1, the tapered portion thereof urges the opposing fastening element 7 upward, as is clear from the vectors indicated by the arrows in FIG. 5. At such time an opposing force urges the fastening element 6 downward in the direction of the spindle 1. As a result, the accommodating ring 2 is rigidly secured on the spindle 1 when the bolts 5 are tightened fully.

Further, by forming the accommodating ring 2 and cover body 4 to have identical outer diameters, the outer circumferential surface of the accommodating ring 2 and the outer circumferential surface of the annular cover body 4 can be made to coincide.

By thus fitting the components together, parting of the accommodating ring 2 from the spindle 1 due to centrifugal force produced at rotation, is prevented. A measure for dealing with such separation of the accommodating ring 2 from the spindle 1 is particularly important since a large centrifugal force acts upon the magnetic body 3 and its accommodating ring 2 when the spindle 1 is being rotated at high velocities of from 10,000 rpm to 20,000 rpm. The present invention realizes this measure through a simple structure.

According to the present invention,

(1) the accommodating ring 2 of the magnetic body 3 is rigidly secured to the spindle 1 by providing the pair of wedge-shaped, annular fastening members 6, 7 the tapered portions of which oppose each other, and tightly fastening the annular cover body 4.

(2) The second projection 4b formed on the annular cover body 4 is fitted into the cut-out portion 2b formed in the outer circumferential portion of the accommodating ring 2 of magnetic body 3. This prevents the magnetic body 3 and accommodating ring 2 from being separated from the spindle 1 by centrifugal force.

(3) Since the outer circumferential surface of the accommodating ring 2 of magnetic body 3 and the outer circumferential surface of the annular cover body 4 are made to coincide, no noise is produced by air resistance even when the spindle is rotated at a high velocity.

(4) Since the object 8 having a mass equivalent to that of the magnetic body 3 is provided at a location symmetrically located with respect to the magnetic body 3 with the central axis of the spindle 1 serving as center, a magnetic sensor system can be constructed in which irregular rotation of the spindle 1 does not occur.

Though the present invention has been described in accordance with the illustrated embodiment, the invention is not limited solely to the embodiment but can be modified in various ways in accordance with the gist thereof, without departing from the scope of the claims.

The present invention can be utilized effectively in a magnetic sensor system for spindle orientation in which the spindle of a machine tool or the like is stopped at a fixed position in a contactless manner, the invention being applied to rigidly attach the magnetic body of the magnetic sensor system to the spindle rotatable at high velocity. 

What is claimed is:
 1. A magnetic sensor system for spindle orientation in which a magnetic body is attached to a rotating spindle and a magnetic signal from the magnetic body is detected by a sensing unit arranged on a mechanically stationary member to detect the rotational position of the spindle, comprising:a pair of wedge-shaped, annular fastening elements fitted onto the circumferential surface of said spindle in such a manner that tapered portions of said wedge-shaped annular fastening elements oppose each other; an accommodating ring having a first cut-out portion on an inner circumferential side thereof adjacent the spindle for receiving said wedge-shaped, annular fastening elements, and having a second cut-out portion on an outer circumferential side thereof, said accommodating ring having an accommodating portion for accommodating the magnetic body; and an annular cover body having a first projection which projects at a position corresponding to said first cut-out portion of said accommodating ring, for sliding said wedge-shaped, annular fastening elements axially along the circumferential surface of the spindle, and having a second projection for being fitted into said second cut-out portion of said accommodating ring; the magnetic body being attached to the spindle by fixedly securing said accommodating ring and said cover body together on the spindle.
 2. A magnetic sensor system for spindle orientation according to claim 1, wherein said accommodating ring accommodates an object having a mass equivalent to that of the magnetic body, and wherein the object is positioned so as to be located symmetrically with respect to the magnetic body about the central axis of the spindle.
 3. A magnetic sensor system for spindle orientation according to claim 1, wherein said accommodating ring and said cover body are formed to have identical outer diameters, and wherein the outer circumferential surfaces of said accommodating ring and said cover body are coincident and free of irregularities.
 4. A magnetic sensor system for spindle orientation according to claim 2, wherein the magnetic body accommodated by said accommodating ring is a magnetic body having flexibility.
 5. A magnetic sensor system for spindle orientation according to claim 2, wherein said accommodating ring is formed to include female screw portions spaced apart equidistantly along the circumference of said accommodating ring, further comprising bolts for fixedly securing said cover body to said accommodating ring by screwing said bolts into said female screw portions of said accommodating ring.
 6. A magnetic sensor system for spindle orientation according to claim 2, wherein said accommodating ring and said cover body are formed to have identical outer diameters, and wherein the outer circumferential surfaces of said accommodating ring and said cover body are coincident and free of irregularities.
 7. A magnetic sensor system for spindle orientation according to claim 3, wherein the magnetic body accommodated by said accommodating ring is a magnetic body having flexibility.
 8. A magnetic sensor system for spindle orientation according to claim 6, wherein the magnetic body accommodated by said accommodating ring is a magnetic body having flexibility.
 9. A magnetic sensor system for spindle orientation according to claim 3, wherein said accommodating ring is formed to include female screw portions spaced apart equidistantly along the circumference of said accommodating ring, further comprising bolts for fixedly securing said cover body to said accommodating ring by screwing said bolts into said female screw portions of said accommodating ring.
 10. A magnetic sensor system for spindle orientation according to claim 6, wherein said accommodating ring is formed to include female screw portions spaced apart equidistantly along the circumference of said accommodating ring, further comprising bolts for fixedly securing said cover body to said accommodating ring by screwing said bolts into said female screw portions of said accommodating ring.
 11. A magnetic sensor system for spindle orientation according to claim 4, wherein said accommodating ring is formed to include female screw portions spaced apart equidistantly along the circumference of said accommodating ring, further comprising bolts for fixedly securing said cover body to said accommodating ring by screwing said bolts into said female screw portions of said accommodating ring.
 12. A magnetic sensor system for spindle orientation according to claim 7, wherein said accommodating ring is formed to include female screw portions spaced apart equidistantly along the circumference of said accommodating ring, further comprising bolts for fixedly securing said cover body to said accommodating ring by screwing said bolts into said female screw portions of said accommodating ring.
 13. A magnetic sensor system for spindle orientation according to claim 8, wherein said accommodating ring is formed to include female screw portions spaced apart equidistantly along the circumference of said accommodating ring, further comprising bolts for fixedly securing said cover body to said accommodating ring by screwing said bolts into said female screw portions of said accommodating ring.
 14. A mounting structure for mounting a magnetic body on a spindle for spindle orientation, comprising:an accommodating ring having an inner circumference capable of sliding over the outer circumference of the spindle, said accommodating ring having an outer circumference and an inner circumference, having a first cut-out portion on the inner circumference, having a second cut-out portion on the outer circumference, and having an accommodating portion for receiving the magnetic body; first and second wedge-shaped annular fastening elements positioned in the first cut-out portion of said accommodating ring, said wedge-shaped annular fastening elements having tapered portions and being arranged so that the tapered portion oppose each other; and an annular cover body fixedly secured to said accommodating ring, said annular cover body having a first projection at a position corresponding to the first cut-out portion of said accommodating ring for urging said wedge-shaped annular fastening elements axially along the circumferential surface of the spindle so as to force said wedge-shaped annular fastening elements against said accommodating ring and the spindle, said annular cover body having a second projection at a position corresponding to the second cut-out portion of said accommodating ring.
 15. A mounting structure according to claim 14, wherein said accommodating ring includes means for accommodating an object having a mass equivalent to the mass of the magnetic body and for positioning the object on said accommodating ring so that it is located symmetrically with respect to the magnetic body about the central axis of the spindle.
 16. A mounting structure according to claim 15, wherein the accommodating portion of said accommodating ring comprises a slot in which the magnetic body is positioned and wherein said annular cover body holds the magnetic body in the slot when said annular cover body is fixedly secured to said accommodating ring.
 17. A mounting structure according to claim 16, wherein said accommodating ring and said annular cover body have identical outer diameters, and wherein the outer circumferences of said accommodating ring and said annular cover body are coincident and free of irregularities.
 18. A mounting structure according to claim 17, wherein the magnetic body which is positioned in the slot in said accommodating ring is a flexible magnetic body.
 19. A mounting structure according to claim 18, wherein the object comprises an attracting magnet.
 20. A mounting structure according to claim 17, further comprising bolts for fixedly securing said annular cover body to said accommodating ring. 